[lttng-dev] beginner question

[Julien Desfossez]

Hi,

On 05/05/12 12:14 AM, Loris Degioanni wrote:
> I just installed the lttng package on a fresh Ubuntu 12 machine, and I'm
> following the tutorial at http://lttng.org/quickstart.
> The enable-event step fails with this error:
> 
> # lttng enable-event sched_switch,sys_open -k
> kernel event sched_switch created in channel channel0
> Error: Event sys_open: Enable kernel event failed (channel channel0,
> session mysession)
> Warning: Some command(s) went wrong
> 
> What am I doing wrong?

As of now, you can't enable system calls tracing one by one (sys_open is
a system call), it's either all of them or none.

So if you want sched_switch and all the syscalls you have to do :
lttng enable-event -k sched_switch
lttng enable-event -k --syscall -a

Have fun,

Julien